New! View global litigation for patent families

US5821733A - Multiple cell and serially connected rechargeable batteries and charging system - Google Patents

Multiple cell and serially connected rechargeable batteries and charging system Download PDF

Info

Publication number
US5821733A
US5821733A US08767170 US76717096A US5821733A US 5821733 A US5821733 A US 5821733A US 08767170 US08767170 US 08767170 US 76717096 A US76717096 A US 76717096A US 5821733 A US5821733 A US 5821733A
Authority
US
Grant status
Grant
Patent type
Prior art keywords
voltage
battery
connected
cells
charging
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US08767170
Inventor
Robert R. Turnbull
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
Packard Bell NEC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/42Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/46Accumulators structurally combined with charging apparatus
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/42Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44Methods for charging or discharging
    • H01M10/441Methods for charging or discharging for several batteries or cells simultaneously or sequentially
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0003Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with provision for charging different types of batteries
    • H02J7/0011Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with provision for charging different types of batteries with charge circuits contained within battery unit
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging several batteries simultaneously or sequentially
    • H02J7/0014Circuits for equalisation of charge between batteries
    • H02J7/0016Circuits for equalisation of charge between batteries using shunting, discharge or bypass circuits
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging several batteries simultaneously or sequentially
    • H02J7/0026Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging several batteries simultaneously or sequentially using safety or protection circuits, e.g. overcharge/discharge disconnection
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0042Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by the mechanical construction
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL INTO ELECTRICAL ENERGY
    • H01M2/00Constructional details or processes of manufacture of the non-active parts
    • H01M2/10Mountings; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M2/1016Cabinets, cases, fixing devices, adapters, racks or battery packs
    • H01M2/1022Cabinets, cases, fixing devices, adapters, racks or battery packs for miniature batteries or batteries for portable equipment
    • H01M2/105Cabinets, cases, fixing devices, adapters, racks or battery packs for miniature batteries or batteries for portable equipment for cells of cylindrical configuration
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL INTO ELECTRICAL ENERGY
    • H01M2/00Constructional details or processes of manufacture of the non-active parts
    • H01M2/20Current conducting connections for cells
    • H01M2/34Current conducting connections for cells with provision for preventing undesired use or discharge, e.g. complete cut of current

Abstract

A battery charging system for multiple series connected battery cells which includes a plurality of shunt regulators, adapted to be connected in parallel with each of the cells. The voltage of each cell is monitored during charging. When a cell is fully charged, excess charging current is shunted around the fully charged cell to enable the remaining cells to continue to charge. Circuitry is also provided to prevent the charging system from discharging the cells when the battery is not being charged. In an alternative battery charging system, a voltage source is connected across each of the serially connected batteries. Each voltage source is capable of sourcing or sending charging current. During charging conditions, the voltage sources source charging current to the cells. In order to prevent fully charged cells from being overcharged, the voltage across each cell is monitored. When the cell becomes fully charged, as indicated by the cell voltage, excess charging current is sunk to ground. In another embodiment of the invention, a rechargeable battery, formed from multiple internally series connected cells is provided with an integral battery charger within the battery housing.

Description

This is a continuation of application Ser. No. 08/200,015, filed Feb. 22, 1994.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rechargeable battery and a battery charging system and, more particularly, to a rechargeable multiple cell battery and battery charging system for simultaneously charging batteries formed from multiple cells connected in series which eliminates the risk of overcharging any of the cells due to poor cell voltage matching.

2. Description of the Prior Art

Rechargeable batteries are known. More particularly, both rechargeable alkaline and nickel cadmium (NiCad) batteries are known. Rechargeable alkaline batteries provide many advantages over rechargeable NiCad batteries. For example, rechargeable alkaline batteries have been found to last up to three times longer per charge than fully charged NiCad batteries. In addition, alkaline batteries have relatively longer shelf lives than comparable NiCad batteries and are free of cadmium which requires special handling under the new environmental regulations.

Charging systems for rechargeable alkaline batteries are also known. However, such rechargeable alkaline battery charging systems have only been used on single cell batteries, such as standard AAA, AA, C and D sizes. However, there are various problems in attempting to charge a multiple cell batteries, such as a 9-volt battery; formed from a plurality of 1.5 volt cells connected in series. In particular, alkaline battery cells are known to have relatively poor cell voltage matching which, in turn, can result in one of the cells connected in series eventually being overcharged. Such overcharging can cause the cell to eventually leak. Thus, known rechargeable alkaline battery charging systems have been limited to single cell batteries. Even in charging systems for charging multiple single cell batteries, each of the single cell batteries is charged independently in such systems. Due to the poor cell voltage matching of multiple cell batteries, charging systems for rechargeable multiple cell alaline batteries, such as a 9V battery, are not available. Since many devices require 9-volt batteries, rechargeable NiCad batteries must be used in such applications. As mentioned above, such NiCad batteries put additional burdens on manufacturers because of the new environmental regulations and also have certain disadvantages relative to the alkaline batteries as discussed above.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a rechargeable multiple cell battery and battery charging system which solves various problems in the prior art.

It is yet another object of the present invention to provide a rechargeable battery formed from a plurality of battery cells internally connected in series which includes a plurality of output terminals to enable such multiple cell batteries to be relatively uniformly charged.

It is yet a further object of the present invention to provide a battery charging system for charging a plurality of battery cells connected in series which virtually eliminates the possibility of overcharging any of the series connected cells due to the relatively poor cell matching of the individual cells.

It is yet another object of the present invention to provide a multiple cell rechargeable battery with an integral battery charger.

Briefly, the present invention relates to a rechargeable multiple cell battery and a battery charging system for multiple series connected battery cells which includes a plurality of shunt regulators, adapted to be connected in parallel with each of the cells. The voltage of each cell is monitored during charging. When a cell is fully charged, excess charging current is shunted around the fully charged cell to enable the remaining cells to continue to charge. Circuitry is also provided to prevent the charging system from discharging the cells when the battery is not being charged. In an alternative battery charging system, a voltage source is connected across each of the serially connected batteries. Each voltage source is capable of sourcing or sinking charging current. During charging conditions, the voltage source sources charging current to the cells. In order to prevent fully charged cells from being overcharged, the voltage across each cell is monitored. When the cell becomes fully charged, as indicated by the cell voltage, excess charging current is sunk to ground. In another embodiment of the invention, a rechargeable battery, formed from multiple internally series connected cells, is provided with an integral battery charger within the battery housing.

DESCRIPTION OF THE DRAWINGS

These and other objects of the present invention will be readily apparent from the following description and attached drawings wherein:

FIG. 1 is a perspective view of a known 9-volt battery which includes six (6) tubular shaped internally series connected 1.5 volt cells, shown with the outer casing removed;

FIG. 2 is a simplified diagram of an alternate embodiment of a known 9-volt battery comprised of a plurality of disc shaped 1.5 volt cells;

FIG. 3 is a perspective view of a multiple cell battery in accordance with the present invention;

FIG. 4 is an end view of an alternative bottom end cap in accordance with the present invention;

FIG. 5 is a schematic representation of the main and auxiliary terminals for the battery illustrated in FIG. 3;

FIG. 6 is a simplified schematic diagram of the charging circuit in accordance with the present invention;

FIG. 7 is a detailed schematic diagram of a battery of charging circuit in accordance with the present invention; and

FIG. 8 is a detailed schematic diagram of an alternative embodiment of the battery charging circuit in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to a multiple cell battery and battery charging system for a multiple cell battery which enables a battery formed from multiple series connected battery cells to be charged without overcharging of any of the individual cells due to poor cell voltage matching. Although the battery charging system, in accordance with the present invention, is primarily disclosed and illustrated relative to a 9-volt alkaline battery formed from six (6) 1.5 volt cells internally connected in series, the principles of the present invention are applicable to virtually any type of multiple cell batteries which have relatively poor cell voltage matching characteristics, such as lithium batteries. In addition, the principles of the present invention are also applicable to a battery charging system for charging a plurality of externally series connected cells, such as a plurality of AA batteries, to enable in-circuit charging without causing overcharging of any of the series connected cells.

Referring to FIG. 1, a conventional 9-volt alkaline battery is shown with its outer housing removed. The battery, generally identified with the reference numeral 20, is formed from six (6) 1.5 volt alkaline cells 22. These cells 22 are connected in series by way of a plurality of conductive straps 24. The positive and negative voltage terminals of the first and last cell 22, respectively, in the series chain are connected to external terminals 26 and 28, by way of electrical conductors 32 such that the voltage across the external terminals 26 and 28 is the sum of all of the cell voltages within the battery. A top end cap 30 and a bottom end cap 34 are used to close the top and bottom of an external housing (not shown); normally disposed around the cells 22. The external terminals 26 and 28 are rigidly secured to the top end cap 30.

FIG. 1 illustrates a known 9-volt battery formed from individual elongated tubular cells 22. FIG. 2 illustrates an alternative construction of a known 9-volt battery wherein each of the individual cells 24 are formed in a disc shape and stacked one on top of the other, thus obviating the need for the conductive straps 24. In this embodiment, the individual terminals of the cells 22 are directly connected to one another to form the series connection.

With both known types of 9-volt batteries illustrated in FIGS. 1 and 2, only two terminals are available on the outside of the housing to connect the battery into a circuit as well as for charging. As mentioned above, alkaline batteries are known to have inherently poor cell voltage matching characteristics. As such, directing a source of charging current through all of the series connected cells 22 can result in overcharging of one or more of cells 22 within the battery. More particularly, due to the poor cell matching characteristics of alkaline batteries, sourcing a charging current through a series connected batteries would result in the cells becoming fully charged at different rates. As such, certain cells would become fully charged before the other cells. By allowing the charging current to continue to flow through all of the series connected cells in such a situation, the cells which first became fully charged would eventually overcharge and possibly become damaged. Thus, known battery charger systems have not addressed the issue of charging series connected cells 22.

FIG. 3 illustrates a multiple cell battery 36 in accordance with the present invention which enables the battery 36 to be charged while virtually eliminating the risk of overcharging individual cells 22 within the battery 36. In particular, the battery 36 is formed in a conventional manner with a plurality of cells 22 connected in series by way of conductive straps 24. The battery 36 further includes an outer housing (not shown) opened at both ends and closed by the end caps 30 and 34. The positive and negative terminals of the first and last cell 22, respectively, in the series chain are connected to the external terminals 26 and 28 as discussed above. However, in accordance with an important aspect of the present invention, the junction of the positive and negative terminals of each of the intermediate cells 22 are connected to auxiliary external terminals 38, illustrated schematically in FIG. 5, by way of electrical conductors 39. The auxiliary terminals 38 may be carried by the top end cap 30, as illustrated in FIG. 3, adjacent the main external terminals 26 and 28. Alternatively, the external auxiliary terminals 39 may be carried by the batteries end cap 34 as illustrated in FIG. 4 and, similarly, connected to the positive and negative terminals of the intermediate cells 22 by way of the electrical conductors 39. In such an embodiment, the plane of the auxiliary terminals 39 may be recessed from the plane of the bottom end cap 34 to reduce the risk of cell shorting when the cell is placed on a conductive surface.

The battery charging circuit, in accordance with the present invention, is illustrated in FIG. 7. FIG. 6 illustrates a simplified representation of the battery charging circuit in accordance with the present invention whereas FIG. 7 represents a detailed embodiment of the battery charging circuit in accordance with the present invention. For simplicity, the charging circuit has only been shown for charging three (3) cells 22. However, the principles of the present invention are clearly applicable to charging any number of series connected battery cells 22.

Referring to FIG. 6, three (3) individual battery cells 22 are connected in series between the main terminals 26 and 28. In this embodiment, since only three (3) cells are being charged, two (2) auxiliary terminals 38 are required. These auxiliary terminals 38, in conjunction with the main terminals 26 and 28, enable shunt regulators 40, shown as Zener diodes for simplicity, to be connected in parallel across each of the series connected cells 22. By connecting the shunt regulators 40 across each of the series connected cells 22, anytime one of the cells 22 becomes fully charged, the shunt regulator 40 shunts the charging current around that cell to prevent damage to that cell while the remaining cells are being charged.

Alkaline battery cells 22 are known to be fully charged when their terminal voltage is about 1.65 volts. Thus, the shunt regulator 40 must be selected to shunt the charging current around the cell 22 whenever the cell voltage exceeds about 1.65 volts DC. Unfortunately, Zener diodes with such low breakdown voltages are relatively inaccurate. As such, use of such Zener diodes in such an application can still result overcharging and possibly damage to one or more of the cells 22 within the battery.

The circuit disclosed in FIG. 7 solves this problem by providing a relatively more accurate control of the current shunting around the cell 22 when the cell is fully charged. Referring to FIG. 7, the battery charging circuit in accordance with the present invention is shown for simplicity for charging three (3) cells. The circuitry includes a plurality of shunt regulators 50 which enable the charging current to the three (3) cells shown 22 to be shunted around individual cells as they become fully charged. Each of the shunt regulators 50 includes a field effect transistor (FET 51 whose drain and source terminals are connected in parallel across each of the cells 22. Each shunt regulator 50 is under the control of a voltage sensing circuit 52 which includes a differential amplifier 54 which senses the actual cell voltage (V1, V2 or V3) of the cell 22 and compares it with a reference voltage VREF. The reference voltage VREF is developed by a circuit identified within the dash box with the reference numeral 56. The outputs of the differential amplifiers 54 are used to control the gates of the FETs 51. If the actual cell voltage (V1, V2 or V3) measured at the cell 22 is greater than the reference voltage VREF, the output of the differential amplifier 54 will be positive to switch the shunt regulator 50 on by turning the FET 51 on to enable the charging current to be shunted around that particular cell 22. Should the actual cell voltage (V1, V2 or V3) be less than the reference voltage VREF, the output of the differential amplifier 54 will be negative keeping the shunt regulators 50 off. During this condition, the charging current will flow through those cells 22 which have not been shunted.

In order to prevent the battery charging circuit from discharging the cells 22 when the battery charger circuit is not being used, a plurality of isolation switches 56, which may be FETs, are provided to disconnect the cells 22 from the battery charging circuit to prevent the battery charging circuit from discharging the cells 22 when the charger is not being utilized. In order to discharge the gate capacitance of the isolation switches 56, a resistor 68 is connected to the gate terminals of each of the isolation switches 56 by way of their respective scaling resistors 64.

The isolation switches 56 are configured to prevent the cells 22 from being discharged by way of the serially connected resistors 66 and 84 when the battery charger is not being used. In particular, the drain and source terminals of each of the isolation switches 56 is connected between the positive terminal of each cell and the resistor 66. The gate terminal of each of the isolation switches 76 is under the control of the input charging voltage supply Vs. More particularly, as shown, a charging voltage supply 58, which provides a charging voltage Vs, is used to develop a charging current Icharge by way of a resistor 60 to charge each of the series connected cells 22. The gate terminal of each of the isolation switches 56 may be connected to the supply voltage Vs by way of a plurality of resistors 62 and 64, which form a voltage divider to control the operation of the isolation switch 56. Thus, when the charging voltage Vs is applied to the cells 22, a positive voltage is developed at the gate terminals of each of the isolation switches 56 to connect the positive terminals of each of the cells 22 to the scaling resistor 66. When the charging voltage Vs is removed or unavailable for charging, the voltage at the gates of each of the isolation switches 56 goes to zero forcing the positive terminals of each of the cells 22 to be disconnected from the scaling resistor 66.

The supply voltage Vs may be provided by way of a conventional alternating current (AC) adapter 67, such as a Model No. SA35-3123, as manufactured by Astec, with a direct current (DC) output, such as 16 VDC. The AC adapter 67 provides a charging current Icharge to charge the series connected cells 22. In order to protect the battery charging circuit, a current limiting resistor 60 and an input diode 61 are provided. The current limiting resistor 60 limits the charging current to the cells 22 as well as the battery charging circuitry. The input protection diode 61 prevents the isolation switches 56 from being turned on by the battery cells 22.

The supply voltage Vs input to the battery charging circuit is under the control of the switching circuit 58 which may include a FET 69, a bipolar junction transistor (BJT) 71 and four resistors 73, 75, 77 and 79. The FET 69 is used to connect and disconnect the output of the AC adapter 67 to the battery charging circuitry. The FET 69 is under the control of the BJT 71, which, in turn, is under the control of a CONTROL INPUT. The CONTROL INPUT may be an output from a microprocessor or any chip that can provide a logical high and low output. When the CONTROL INPUT is high, the gate of the FET 69 is pulled low to disconnect the AC adapter 67 from the battery charging circuit. Alternatively, when the CONTROL INPUT is low, the gate of the FET 69 will be high to connect the AC adapter 67 to the battery charging circuitry.

As mentioned above, the reference voltage VREF is developed by the circuit identified within the dash box 56 which includes a differential amplifier 70, a plurality of serially connected resistors 72, 74 and 76, and a Zener diode 78. The resistors 72, 74 and 76 form a voltage divider to divide the voltage from the power supply voltage Vs to develop a cell voltage Vcell that is applied to the positive terminal of the differential amplifier 70. The Zener diode 78 regulates the voltage applied to the positive input of the differential amplifier 70. The output of the differential amplifier 70 is connected to its negative input to form a unity gain buffer to provide an output voltage VREF, virtually identical to the regulated voltage applied to the positive terminal of the differential amplifier 70. This output voltage VREF, in turn, is applied to the negative inputs of each of the difference amplifiers 54 by way of scaling resistors 80. These scaling resistors 80, in conjunction with resistors 82, connected between the negative junction of the difference amplifiers 54 and ground, enable the reference voltage VREF to be scaled to a predetermined value at the negative input of each of the difference amplifiers 54. Similarly, the actual cell voltages (V1, V2 or V3), applied to the positive inputs of each of the difference amplifiers 54, may likewise be scaled by way of the respective scaling resistors 66 and 84, connected between the positive input of the difference amplifiers 54 and ground. Preferably, the values of the scaling resistor pairs 66 and 82, as well as 80 and 84, should be equal.

In accordance with an important aspect of the invention, the circuitry illustrated in FIG. 7 can be formed as a printed circuit board (PCB) and incorporated within a multiple cell battery housing. In particular, various embodiments of the battery are contemplated. In one embodiment, the PCB incorporating the battery charging circuit illustrated in FIG. 7 may be formed as the bottom end cap 34 illustrated in FIG. 3. In yet an alternate embodiment of the invention, the circuitry disclosed in FIG. 7 could be incorporated into a flexible PCB and used to form the outer housing around the battery. In both embodiments, external auxiliary contacts 38 would not be required since the required connections between the positive and negative terminals of each of the respective cells 22 could be made within the battery housing. As such, in such embodiments, the battery would be formed with only two external terminals 26 and 28 to enable the battery to be connected in a circuit or, alternatively, to external source charging voltage or current.

An alternative embodiment of the battery charging circuit is illustrated in FIG. 8. In this embodiment, a voltage source 102, 104 or 106 is connected across each of the serially connected battery cells 22. Each of the voltage sources 102, 104 and 106 is adapted to source current to its associated battery cell 22 during a charging condition. In addition, two of the voltage sources 104 and 106 are also adapted to sink current to prevent overcharging of certain of the battery cells 22. In particular, the voltage source 102 is a floating voltage source and sources charging current anytime the battery cell 22 connected between nodes V2 and V3 is less than a desired voltage. Since the voltage source 102 is connected to the first battery cell 22 in the serially connected chain, it is not necessary for the voltage source 102 to sink current during any of the conditions. However, the voltage sources 104 and 106 must be able to source current for charging and additionally sink current to prevent overcharging of various of the downstream battery cells 22.

Each of the voltage sources 102, 104 and 106 is configured as a differential amplifier which includes an operational amplifier 108 and 2 to 4 input scaling resistors 110, 112, 114 and 116. In particular, as shown, the voltage source 102 is connected across the battery cell 22 disposed the nodes V2 and V3. More specifically, the negative terminal of the differential amplifier 108 is connected to the positive terminal of the battery cell 22 and referenced to a reference voltage VREF by way of the resistors 110 and 112. The positive terminal of the differential amplifier 108 is connected to the negative terminal of the battery cell 22 connected between the nodes V2 and V3, and referenced to ground by way of the input scaling resistors 114 and 116. With such a configuration, the voltage source 102 will float and charge the battery cell 22 (connected between the nodes V2 and V3) any time the voltage across that cell 22 falls below the reference voltage VREF. More particularly, the voltage applied to the positive terminal of the differential amplifier 108 is connected to the negative terminal of the battery cell 22 which coincides with the node V2. The voltage at the node V2 is equal to the sum of the cell voltages connected between the node V2 and ground. During ideal conditions (i.e., cells fully charged), the voltage at the node V2 will be twice the reference voltage VREF. The voltage applied to the negative terminal of the differential amplifier 108 is the positive terminal of the battery cell 22 connected between the nodes V2 and V3, referenced to a reference voltage VREF. During ideal conditions, the node voltage V3 will be three times the reference voltage VREF. However, since the voltage applied to the negative terminal of the differential amplifier 108 is referenced to the reference voltage VREF, the voltage applied to the negative terminal of the differential amplifier 108 will only be twice VREF during ideal conditions. By sizing the resistors 110, 112, 114 and 116 to have the same value, the differential amplifier 108 will track the voltage across the battery cell 22 connected between the nodes V2 and V3 such that any time the voltage of that cell 22 falls below VREF, the output voltage of the differential amplifier 108 will go positive and provide a charging current to the cell 22 connected between the nodes V2 and V3. In order to limit the charging current applied to the battery cells 22, a current limiting resistor 118 is connected between the output of the differential amplifier 108 and the positive cell terminal.

An important aspect of the circuitry illustrated in FIG. 8 is that once the downstream cells 22 (i.e., connected between the node V2 and ground) become fully charged before the cell connected between the nodes V2 and V3 becomes fully charged, the voltage sources 104 and 106 act to sink the charging current sourced by the voltage source 102 which normally would flow through all three of the serially connected battery cells in order to prevent overcharging of any fully charged cells connected downstream. Since the voltage source 102 is connected to the first cell in the series connected string, the voltage source 102 does not sink current during any condition.

The differential amplifier 108 that forms a portion of the voltage source 104 is connected across the battery cell 22, connected between the nodes V1 and V2. The negative terminal of the differential amplifier 108 of the voltage source 104 is connected to the plus positive terminal of the battery cell 22 connected between the nodes V1 and V2 referenced to the reference voltage VREF. The positive terminal of the differential amplifier 108 is connected to the negative terminal of the battery cell 22 connected between the nodes V1 and V2, referenced to ground. Thus, the voltage applied to the negative terminal of the differential amplifier 108 is equal to the node voltage V2. This node voltage V2 is equal to the algebraic sum of the two serially connected battery cells 22 connected between the node V2 and ground. Since the voltage applied to the negative terminal of the differential amplifier 108 is referenced to VREF, the voltage applied at the input of the negative terminal will be V2 minus VREF. By sizing the input scaling resistors 110 and 112 to be equal, this voltage will be 1/2 V2 minus VRER. During ideal conditions when V2 is equal to twice VREF, the voltage applied to the negative terminal of the differential amplifier 108 will be VREF. The voltage applied to the positive terminal of the differential amplifier 108 will be V1. By proper sizing of the input scaling resistors 114 and 116, the voltage applied to the positive terminal of the differential amplifier 108 will be 1/2 V1, since the positive terminal is referenced to ground. Thus, the voltage source 104 will monitor the voltage across the cell connected between the nodes V1 and V2 and provide a positive output voltage anytime that cell voltage falls below VREF. When the voltage across that cell 22 falls below VREF, the differential amplifier 108 will output a positive voltage in order to provide a charging current which will nominally flow through the two serially connected battery cells 22 connected between the node V2 and ground.

As mentioned above, each of the voltage sources 104 and 106 is able to sink current as well as source current. Thus, should the battery cell 22 connected between the nodes V1 and V2 become fully charged prior to the cell connected between the nodes V2 and V3, the voltage source 104 will sink the charging current flowing through the battery cell 22 connected between the nodes V2 and V3 through to ground by way of the output of its differential amplifier 108 since the voltage at the positive terminal of the battery cell connected to the node V2 will be relatively more positive relative to the output of the differential amplifier 108. By sinking the charging current during such a condition, the battery cell connected between the nodes V1 and V2 will not become overcharged.

In order to limit power dissipation, an additional network may be provided for the voltage source 104, as well as the voltage source 106, which provides a different resistance for the voltage source 104 in a current sinking mode as opposed to a current sourcing mode. In particular, a diode 120 and serially connected resistor 122 may be connected in parallel with each of the current limiting resistors 118 for the voltage sources 104 and 106. By connecting the polarity of the diode 120 as shown, the effective resistance for the voltage sources 104 and 106 will be equivalent to the value of the current limiting resistance 118 in a current sourcing mode. However, in a current sinking mode, the diodes 120 will be biased such that the resistance in a current sinking mode is equivalent to the resistance of the parallel combination of the resistances 122 and 118.

The voltage source 106 is similar to the voltage sources 102 and 104 except the positive terminal of its differential amplifier 108 is referenced to ground. As such, there is no need for the input scaling resistors 114 and 116 on the voltage source 106. The negative terminal of the differential amplifier 108 is connected to the positive terminal of the battery cell 22 connected between the node V1 and ground. The negative terminal is referenced to the reference voltage VREF. Thus, by sizing the input scaling resistors 110 and 112 to have the same value, the input to the negative terminal of the differential amplifier 108 will be equivalent to 1/2 the difference of V1 minus VREF. Thus, during ideal conditions (i.e., V1 =VREF), ground potential will be applied to the negative terminal of the differential amplifier 108. However, when the cell voltage falls below VREF, the differential amplifier 108 of the voltage source 106 will provide a positive output which will provide a charging current to charge the battery cell 22 connected between the node V1 and ground. Should the battery cell 22 connected between V1 and ground become fully charged prior to any of the remaining cells, the voltage source 106 will sink current to ground by way of the output of the differential amplifier 108 in a manner as discussed above.

As mentioned above, the input scaling resistors 110, 112, 114 and 116 are selected to be equal in value, whenever the reference voltage VREF is selected to be equivalent to the desired cell voltage when the cell is fully charged. However, principles of the present invention are applicable to any reference voltage. However, should alternative reference voltages be selected, the values of the scaling resistors 110, 112, 114 and 116 would have to be adjusted accordingly.

In order to prevent the circuitry illustrated in FIG. 8 from discharging the battery cells 22 when no battery supply voltage Vin is available, a plurality of isolation switches 124 are provided to disconnect the battery cells from the circuitry during such a condition. Each of the isolation switches 124 is configured as a field effect transistor (FET) having source, drain and gate terminals. The gate terminals of each of the FETs 124 are connected together and connected to the charging supply voltage Vin. Thus, when charging supply voltage Vin is available, the FETs 124 will all be on to connect the battery cells 22 to the circuitry illustrated in FIG. 8. If the supply voltage Vin is removed, the FETs 124 will turn off in order to disconnect the battery cells 22 from the circuitry illustrated in FIG. 8. A resistor 126 is connected between the gates of each of the FETs 124 and ground. This resistor 126 is used to discharge any gate capacitance in the FETs 124.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. Thus, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically designate above.

Claims (6)

What is desired to be claimed by a Letters Patent is:
1. A battery charging system for charging a plurality of serially connected battery cells comprising:
means for providing charging current to said plurality of serially connected cells;
means for sensing the voltage across each of said serially connected cells;
means responsive to said sensing means for shunting the charging current around individual cells whose voltage is above a predetermined value; and
means for disconnecting said plurality of serially connected cells from said battery charging system to prevent substantially any discharge of said plurality of serially connected cells when said providing means is disconnected from said plurality of serially connected cells, said disconnecting means including one or more voltage activated electronic switches.
2. A battery charging system as recited in claim 1, wherein said sensing means includes differential amplifiers for comparing the voltage of each of the cells with a predetermined reference voltage.
3. A method for charging a plurality of serially connected battery cells comprising the steps of:
(a) providing a charging current to said cells;
(b) sensing the voltage across each of said cells;
(c) shunting the charging current around each cell whose voltage is greater than a predetermined value; and
(d) disconnecting said plurality of serially connected cells from said charging current using one or more voltage activated electronic switches to prevent substantially any discharge of said plurality of serially connected cells when said charring current is disconnected from said plurality of serially connected cells.
4. A battery charging system for a plurality of serially connected battery cells comprising:
means for sourcing charging current to each of said serially connected cells;
means for sensing the voltage across each of said serially connected cells;
means responsive to said sensing means for sinking current to ground around any cell whose voltage is above a predetermined value; and
means for disconnecting said plurality of serially connected cells from said battery charging system to prevent substantially any discharge of said plurality of serially connected cells when said providing means is disconnected from said plurality of serially connected cells, said disconnecting means including one or more voltage activated electronic switches.
5. A battery charging system as recited in claim 4, wherein said sensing means includes a plurality of differential amplifiers, each connected across the positive and negative terminals of each of the cells.
6. A battery charging system as recited in claim 4, wherein said electronic switches include a field effect transistor (FET).
US08767170 1994-02-22 1996-12-16 Multiple cell and serially connected rechargeable batteries and charging system Expired - Lifetime US5821733A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US20001594 true 1994-02-22 1994-02-22
US08767170 US5821733A (en) 1994-02-22 1996-12-16 Multiple cell and serially connected rechargeable batteries and charging system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08767170 US5821733A (en) 1994-02-22 1996-12-16 Multiple cell and serially connected rechargeable batteries and charging system

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US20001594 Continuation 1994-02-22 1994-02-22

Publications (1)

Publication Number Publication Date
US5821733A true US5821733A (en) 1998-10-13

Family

ID=22739961

Family Applications (2)

Application Number Title Priority Date Filing Date
US08767170 Expired - Lifetime US5821733A (en) 1994-02-22 1996-12-16 Multiple cell and serially connected rechargeable batteries and charging system
US08785474 Expired - Lifetime US5747964A (en) 1994-02-22 1997-01-17 Rechargeable battery and charging system

Family Applications After (1)

Application Number Title Priority Date Filing Date
US08785474 Expired - Lifetime US5747964A (en) 1994-02-22 1997-01-17 Rechargeable battery and charging system

Country Status (1)

Country Link
US (2) US5821733A (en)

Cited By (66)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5982144A (en) * 1997-07-14 1999-11-09 Johnson Research & Development Company, Inc. Rechargeable battery power supply overcharge protection circuit
US6025696A (en) * 1998-03-27 2000-02-15 Space Systems/Loral, Inc. Battery cell bypass module
US6242129B1 (en) 1999-04-02 2001-06-05 Excellatron Solid State, Llc Thin lithium film battery
US6268714B1 (en) * 1999-05-07 2001-07-31 Tai-Her Yang Voltage limiting circuit connected in parallel with a battery set and including a series-connected impedance which permits linear adjustments
US6326767B1 (en) 1999-03-30 2001-12-04 Shoot The Moon Products Ii, Llc Rechargeable battery pack charging system with redundant safety systems
US6387563B1 (en) 2000-03-28 2002-05-14 Johnson Research & Development, Inc. Method of producing a thin film battery having a protective packaging
US6388423B1 (en) 2001-02-23 2002-05-14 John W. Schilleci, Jr. Battery monitor and open circuit protector
US6398824B1 (en) 1999-04-02 2002-06-04 Excellatron Solid State, Llc Method for manufacturing a thin-film lithium battery by direct deposition of battery components on opposite sides of a current collector
US6402796B1 (en) 2000-08-07 2002-06-11 Excellatron Solid State, Llc Method of producing a thin film battery
US6423106B1 (en) 2000-04-05 2002-07-23 Johnson Research & Development Method of producing a thin film battery anode
US20020110733A1 (en) * 2000-08-07 2002-08-15 Johnson Lonnie G. Systems and methods for producing multilayer thin film energy storage devices
US6452363B1 (en) 2000-12-28 2002-09-17 C. E. Niehoff & Co. Multiple battery charge equalizer
US6459243B1 (en) 2001-12-14 2002-10-01 Zinc Matrix Power, Inc. Multiple plateau battery charging method and system to fully charge the first plateau
US20030002236A1 (en) * 2001-05-31 2003-01-02 Seiichi Anzawa Current breaker circuit for storage devices, voltage detection circuit for storage devices and abnormality detection circuit
US6511516B1 (en) 2000-02-23 2003-01-28 Johnson Research & Development Co., Inc. Method and apparatus for producing lithium based cathodes
US6522102B1 (en) 2001-12-14 2003-02-18 Zinc Matrix Power, Inc. Multiple plateau battery charging method and system to charge to the second plateau
US20030090234A1 (en) * 2001-11-09 2003-05-15 Glasgow Kevin L. Battery charger
US20030111979A1 (en) * 2001-12-16 2003-06-19 Michael Cheiky Battery charging system
US6582481B1 (en) 1999-11-23 2003-06-24 Johnson Research & Development Company, Inc. Method of producing lithium base cathodes
US20030151391A1 (en) * 2002-02-08 2003-08-14 John Cummings Circuits, apparatuses, electrochemical device charging methods, and lithium-mixed metal electrode cell charging methods
US20030151389A1 (en) * 2002-02-08 2003-08-14 John Cummings Electrical power source apparatuses, circuits, electrochemical device charging methods, and methods of charging a plurality of electrochemical devices
WO2003096471A1 (en) * 2002-05-09 2003-11-20 Moby Power Co., Ltd Rechargeable battery pack
US20040012913A1 (en) * 2000-10-02 2004-01-22 Andelman Marc D. Fringe-field capacitor electrode for electrochemical device
US20040032947A1 (en) * 2002-04-29 2004-02-19 Nattkemper Dieter H. Element management system for managing line-powered network elements
US20040121204A1 (en) * 2001-06-07 2004-06-24 Adelman Marc D. Fluid electrical connected flow-through electrochemical cells, system and method
US6806686B1 (en) 2003-04-25 2004-10-19 Maxwell Technologies, Inc. Charge balancing circuit
US20040263121A1 (en) * 2003-04-25 2004-12-30 Maxwell Technologies, Inc. Charge balancing circuit for double-layer capacitors
US20050008772A1 (en) * 2003-07-11 2005-01-13 Ji-Guang Zhang System and method of producing thin-film electrolyte
US20050016458A1 (en) * 2003-07-11 2005-01-27 Ji-Guang Zhang Apparatus for producing thin-film electrolyte
US20050024021A1 (en) * 2003-05-07 2005-02-03 Milwaukee Electric Tool Corporation Battery charger and assembly
US20050076551A1 (en) * 2003-08-11 2005-04-14 Aaron Silverstone Solar illuminated address sign
US20050170256A1 (en) * 2004-01-30 2005-08-04 John Cummings Electrical power source apparatuses, electrical power source operational methods, and electrochemical device charging methods
US20050200332A1 (en) * 2004-03-11 2005-09-15 International Business Machines Corporation Intelligent multiple battery charging station
US20050208353A1 (en) * 2004-02-20 2005-09-22 Johnson Lonnie G Lithium oxygen batteries and method of producing same
US20050266300A1 (en) * 2004-02-13 2005-12-01 Joseph Lamoreux Electrical energy supply methods and electrical energy power supplies
US20050275374A1 (en) * 2004-06-09 2005-12-15 Guang Huang T Pseudo constant current multiple cell battery charger configured with a parallel topology
US20050275373A1 (en) * 2004-06-09 2005-12-15 Guang Huang T Multiple cell battery charger configured with a parallel topology
EP1641099A1 (en) * 2004-09-24 2006-03-29 Conception et Développement Michelin S.A. Detachable charge control circuit for balancing the voltage of supercapacitors connected in series
US20060082345A1 (en) * 2004-08-26 2006-04-20 Josef Daniel-Ivad Rechargeable alkaline battery with overcharging protection
US20060097700A1 (en) * 2004-11-10 2006-05-11 Eaglepicher Technologies, Llc Method and system for cell equalization with charging sources and shunt regulators
US20060097697A1 (en) * 2004-11-10 2006-05-11 Eaglepicher Technologies, Llc Method and system for cell equalization with switched charging sources
US20060097696A1 (en) * 2004-11-10 2006-05-11 Eaglepicher Technologies, Llc Method and system for cell equalization with isolated charging sources
US7199488B1 (en) * 2004-10-14 2007-04-03 Baker David A Telemetry power system
US7204862B1 (en) 2002-01-10 2007-04-17 Excellatron Solid State, Llc Packaged thin film batteries and methods of packaging thin film batteries
US20070094865A1 (en) * 2002-01-10 2007-05-03 Ji-Guang Zhang Packaged thin film batteries and methods of packaging thin film batteries
US20070099078A1 (en) * 2002-01-10 2007-05-03 Ji-Guang Zhang Packaged thin film batteries and methods of packaging thin film batteries
US20080070087A1 (en) * 2004-02-20 2008-03-20 Excellatron Solid State, Llc Non-volatile cathodes for lithium oxygen batteries and method of producing same
US20080258684A1 (en) * 2007-04-20 2008-10-23 Sony Corporation Battery system
US20090004371A1 (en) * 2007-06-29 2009-01-01 Johnson Lonnie G Amorphous lithium lanthanum titanate thin films manufacturing method
US20090092903A1 (en) * 2007-08-29 2009-04-09 Johnson Lonnie G Low Cost Solid State Rechargeable Battery and Method of Manufacturing Same
US20090098281A1 (en) * 2005-10-11 2009-04-16 Ji-Guang Zhang Method of manufacturing lithium battery
US20090239132A1 (en) * 2008-03-20 2009-09-24 Excellatron Solid State, Llc Oxygen battery system
US20090257580A1 (en) * 2002-04-29 2009-10-15 Adc Dsl Systems, Inc. Function for controlling line powered network element
US7696089B1 (en) 2004-05-11 2010-04-13 Johnson Research & Development Co., Inc. Passivated thin film and method of producing same
US7731765B2 (en) 2004-02-20 2010-06-08 Excellatron Solid State, Llc Air battery and manufacturing method
US20100141210A1 (en) * 2009-12-07 2010-06-10 Remy Technologies, L.L.C. Alternator for charging multiple electric storage devices
US20110003182A1 (en) * 2009-07-06 2011-01-06 Amperex Technology Limited Connection scheme for multiple battery cells
US20110053001A1 (en) * 2008-06-27 2011-03-03 Excellatron Solid State Llc Ionically-conductive amorphous lithium lanthanum zirconium oxide
US20110089902A1 (en) * 2009-10-21 2011-04-21 K2 Energy Solutions, Inc. Circuitry for balancing charging of series connected battery cells
US20110175573A1 (en) * 2008-08-28 2011-07-21 Tomoyoshi Ueki Assembled battery and assembled battery control system
US8568921B1 (en) 2004-08-18 2013-10-29 Excellatron Solid State Llc Regenerative ion exchange fuel cell
US8866412B2 (en) 2011-01-11 2014-10-21 Braxton Engineering, Inc. Source and multiple loads regulator
US9240696B2 (en) 2010-07-15 2016-01-19 Zpower, Llc Method and apparatus for recharging a battery
US9356317B2 (en) 2007-06-29 2016-05-31 Johnson Ip Holding, Llc Amorphous ionically conductive metal oxides and sol gel method of preparation
US9466991B2 (en) 2013-04-25 2016-10-11 Industrial Technology Research Institute Matrix charger apparatus and charging method
US9793525B2 (en) 2012-10-09 2017-10-17 Johnson Battery Technologies, Inc. Solid-state battery electrodes

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5776743A (en) 1994-09-06 1998-07-07 La Jolla Cancer Research Foundation Method of sensitizing tumor cells with adenovirus E1A
US6037750A (en) * 1998-09-17 2000-03-14 Qualcomm Incorporated Battery pack controller
US6172479B1 (en) 1999-03-04 2001-01-09 Baxter International Inc. Battery control circuit
US7215318B2 (en) * 2002-06-24 2007-05-08 Gentex Corporation Electrochromic element drive control circuit
US20060113956A1 (en) * 2003-05-07 2006-06-01 Bublitz Scott D Battery charger and assembly
US7105249B2 (en) * 2003-06-03 2006-09-12 Hall David R Pressure-compensated downhole battery
DE102004020176A1 (en) * 2004-04-24 2005-11-17 Robert Bosch Gmbh Charger for a rechargeable battery
DE102004030083A1 (en) * 2004-06-22 2006-01-12 A1, Light And More Lichttechnik Gmbh Energy storage device
US7667432B2 (en) * 2006-04-27 2010-02-23 Tesla Motors, Inc. Method for interconnection of battery packs and battery assembly containing interconnected battery packs
CN101636892B (en) * 2006-11-10 2013-03-27 锂平衡公司 A battery management system
US20110175571A1 (en) * 2007-10-19 2011-07-21 Troy Renken Charger and method for charging for silver zinc batteries

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4238721A (en) * 1979-02-06 1980-12-09 The United States Of America As Represented By The United States Department Of Energy System and method for charging electrochemical cells in series
US4303877A (en) * 1978-05-05 1981-12-01 Brown, Boveri & Cie Aktiengesellschaft Circuit for protecting storage cells
US4713597A (en) * 1985-12-04 1987-12-15 Powerplex Technologies, Inc. Silicon diode looping element for protecting a battery cell
US5206577A (en) * 1991-09-30 1993-04-27 Fish Robert D Battery charger

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5270635A (en) * 1989-04-11 1993-12-14 Solid State Chargers, Inc. Universal battery charger

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4303877A (en) * 1978-05-05 1981-12-01 Brown, Boveri & Cie Aktiengesellschaft Circuit for protecting storage cells
US4238721A (en) * 1979-02-06 1980-12-09 The United States Of America As Represented By The United States Department Of Energy System and method for charging electrochemical cells in series
US4713597A (en) * 1985-12-04 1987-12-15 Powerplex Technologies, Inc. Silicon diode looping element for protecting a battery cell
US5206577A (en) * 1991-09-30 1993-04-27 Fish Robert D Battery charger

Cited By (114)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5982144A (en) * 1997-07-14 1999-11-09 Johnson Research & Development Company, Inc. Rechargeable battery power supply overcharge protection circuit
US6025696A (en) * 1998-03-27 2000-02-15 Space Systems/Loral, Inc. Battery cell bypass module
US6489751B2 (en) 1999-03-30 2002-12-03 Shoot The Moon Products Ii, Llc Methods and apparatuses for rechargeable battery pack chargers
US6326767B1 (en) 1999-03-30 2001-12-04 Shoot The Moon Products Ii, Llc Rechargeable battery pack charging system with redundant safety systems
US6398824B1 (en) 1999-04-02 2002-06-04 Excellatron Solid State, Llc Method for manufacturing a thin-film lithium battery by direct deposition of battery components on opposite sides of a current collector
US6242129B1 (en) 1999-04-02 2001-06-05 Excellatron Solid State, Llc Thin lithium film battery
US6268714B1 (en) * 1999-05-07 2001-07-31 Tai-Her Yang Voltage limiting circuit connected in parallel with a battery set and including a series-connected impedance which permits linear adjustments
US6582481B1 (en) 1999-11-23 2003-06-24 Johnson Research & Development Company, Inc. Method of producing lithium base cathodes
US6511516B1 (en) 2000-02-23 2003-01-28 Johnson Research & Development Co., Inc. Method and apparatus for producing lithium based cathodes
US6387563B1 (en) 2000-03-28 2002-05-14 Johnson Research & Development, Inc. Method of producing a thin film battery having a protective packaging
US6423106B1 (en) 2000-04-05 2002-07-23 Johnson Research & Development Method of producing a thin film battery anode
US6402796B1 (en) 2000-08-07 2002-06-11 Excellatron Solid State, Llc Method of producing a thin film battery
US20020110733A1 (en) * 2000-08-07 2002-08-15 Johnson Lonnie G. Systems and methods for producing multilayer thin film energy storage devices
US20040012913A1 (en) * 2000-10-02 2004-01-22 Andelman Marc D. Fringe-field capacitor electrode for electrochemical device
US6781817B2 (en) 2000-10-02 2004-08-24 Biosource, Inc. Fringe-field capacitor electrode for electrochemical device
US6452363B1 (en) 2000-12-28 2002-09-17 C. E. Niehoff & Co. Multiple battery charge equalizer
US6388423B1 (en) 2001-02-23 2002-05-14 John W. Schilleci, Jr. Battery monitor and open circuit protector
US6754058B2 (en) * 2001-05-31 2004-06-22 Nagano Japan Radio Co., Ltd. Current breaker circuit for storage devices, and abnormality detection circuit
US20030002236A1 (en) * 2001-05-31 2003-01-02 Seiichi Anzawa Current breaker circuit for storage devices, voltage detection circuit for storage devices and abnormality detection circuit
US20040121204A1 (en) * 2001-06-07 2004-06-24 Adelman Marc D. Fluid electrical connected flow-through electrochemical cells, system and method
US20080100261A1 (en) * 2001-11-09 2008-05-01 Glasgow Kevin L Battery charger
US7332889B2 (en) 2001-11-09 2008-02-19 Milwaukee Electric Tool Corporation Battery charger
US20030090234A1 (en) * 2001-11-09 2003-05-15 Glasgow Kevin L. Battery charger
US6459243B1 (en) 2001-12-14 2002-10-01 Zinc Matrix Power, Inc. Multiple plateau battery charging method and system to fully charge the first plateau
US6522102B1 (en) 2001-12-14 2003-02-18 Zinc Matrix Power, Inc. Multiple plateau battery charging method and system to charge to the second plateau
US7218076B2 (en) 2001-12-16 2007-05-15 Zinc Matrix Power, Inc. Battery charging system
US6943529B2 (en) 2001-12-16 2005-09-13 Zinc Matrix Power, Inc. Battery charging system
US6943530B2 (en) 2001-12-16 2005-09-13 Zinc Matrix Power, Inc. Battery charging system
US20030111979A1 (en) * 2001-12-16 2003-06-19 Michael Cheiky Battery charging system
US20040178772A1 (en) * 2001-12-16 2004-09-16 Michael Cheiky Battery charging system
US20040217738A1 (en) * 2001-12-16 2004-11-04 Michael Cheiky Battery charging system
US20070094865A1 (en) * 2002-01-10 2007-05-03 Ji-Guang Zhang Packaged thin film batteries and methods of packaging thin film batteries
US7960054B2 (en) 2002-01-10 2011-06-14 Excellatron Solid State Llc Packaged thin film batteries
US7204862B1 (en) 2002-01-10 2007-04-17 Excellatron Solid State, Llc Packaged thin film batteries and methods of packaging thin film batteries
US20070099078A1 (en) * 2002-01-10 2007-05-03 Ji-Guang Zhang Packaged thin film batteries and methods of packaging thin film batteries
US20050212485A1 (en) * 2002-02-08 2005-09-29 John Cummings Circuits, Apparatuses, Electrochemical Device Charging Methods, and Lithium-Mixed Metal Electrode Cell Charging Methods
US6919708B2 (en) 2002-02-08 2005-07-19 Valence Technology, Inc. Electrical storage circuitry operational methods
US20030151389A1 (en) * 2002-02-08 2003-08-14 John Cummings Electrical power source apparatuses, circuits, electrochemical device charging methods, and methods of charging a plurality of electrochemical devices
US6798170B2 (en) * 2002-02-08 2004-09-28 Valence Technology, Inc. Electrical power source apparatuses, circuits, electrochemical device charging methods, and methods of charging a plurality of electrochemical devices
US20030151391A1 (en) * 2002-02-08 2003-08-14 John Cummings Circuits, apparatuses, electrochemical device charging methods, and lithium-mixed metal electrode cell charging methods
US6724173B2 (en) * 2002-02-08 2004-04-20 Valence Technology, Inc. Circuits, apparatuses, electrochemical device charging methods, and lithium-mixed metal electrode cell charging methods
US7019487B2 (en) * 2002-02-08 2006-03-28 Valence Technology, Inc. Circuits, apparatuses, electrochemical device charging methods, and lithium-mixed metal electrode cell charging methods
US20040196008A1 (en) * 2002-02-08 2004-10-07 Valence Technology Circuits, apparatuses, electrochemical device charging methods, and lithium-mixed metal electrode cell charging methods
US8073134B2 (en) 2002-04-29 2011-12-06 Adc Dsl Systems, Inc. Function for controlling line powered network element
US7599484B2 (en) * 2002-04-29 2009-10-06 Adc Dsl Systems, Inc. Element management system for managing line-powered network elements
US20040032947A1 (en) * 2002-04-29 2004-02-19 Nattkemper Dieter H. Element management system for managing line-powered network elements
US20090257580A1 (en) * 2002-04-29 2009-10-15 Adc Dsl Systems, Inc. Function for controlling line powered network element
WO2003096471A1 (en) * 2002-05-09 2003-11-20 Moby Power Co., Ltd Rechargeable battery pack
US20040212346A1 (en) * 2003-04-25 2004-10-28 Maxwell Technologies, Inc. Charge balancing circuit
US6806686B1 (en) 2003-04-25 2004-10-19 Maxwell Technologies, Inc. Charge balancing circuit
US20040263121A1 (en) * 2003-04-25 2004-12-30 Maxwell Technologies, Inc. Charge balancing circuit for double-layer capacitors
US20050024021A1 (en) * 2003-05-07 2005-02-03 Milwaukee Electric Tool Corporation Battery charger and assembly
US7659696B2 (en) 2003-05-07 2010-02-09 Milwaukee Electric Tool Corporation Battery charger and assembly
US20080036420A1 (en) * 2003-05-07 2008-02-14 Zeiler Jeffrey M Battery charger and assembly
US6886240B2 (en) 2003-07-11 2005-05-03 Excellatron Solid State, Llc Apparatus for producing thin-film electrolyte
US20050016458A1 (en) * 2003-07-11 2005-01-27 Ji-Guang Zhang Apparatus for producing thin-film electrolyte
US6852139B2 (en) 2003-07-11 2005-02-08 Excellatron Solid State, Llc System and method of producing thin-film electrolyte
US20050008772A1 (en) * 2003-07-11 2005-01-13 Ji-Guang Zhang System and method of producing thin-film electrolyte
US20050076551A1 (en) * 2003-08-11 2005-04-14 Aaron Silverstone Solar illuminated address sign
US20050170256A1 (en) * 2004-01-30 2005-08-04 John Cummings Electrical power source apparatuses, electrical power source operational methods, and electrochemical device charging methods
US20050266300A1 (en) * 2004-02-13 2005-12-01 Joseph Lamoreux Electrical energy supply methods and electrical energy power supplies
US7719227B2 (en) 2004-02-13 2010-05-18 Valence Technology, Inc. Electrical energy supply methods and electrical energy power supplies
US20080070087A1 (en) * 2004-02-20 2008-03-20 Excellatron Solid State, Llc Non-volatile cathodes for lithium oxygen batteries and method of producing same
US7691536B2 (en) 2004-02-20 2010-04-06 Excellatron Solid State, Llc Lithium oxygen batteries and method of producing same
US7731765B2 (en) 2004-02-20 2010-06-08 Excellatron Solid State, Llc Air battery and manufacturing method
US20050208353A1 (en) * 2004-02-20 2005-09-22 Johnson Lonnie G Lithium oxygen batteries and method of producing same
US7253586B2 (en) 2004-03-11 2007-08-07 Lenovo (Singapore) Pte. Ltd. Intelligent multiple battery charging station
US20050200332A1 (en) * 2004-03-11 2005-09-15 International Business Machines Corporation Intelligent multiple battery charging station
US7696089B1 (en) 2004-05-11 2010-04-13 Johnson Research & Development Co., Inc. Passivated thin film and method of producing same
WO2005124965A3 (en) * 2004-06-09 2006-03-16 Internat Components Corp Multiple cell battery charger configured with a parallel topology
WO2005124965A2 (en) * 2004-06-09 2005-12-29 International Components Corporation Multiple cell battery charger configured with a parallel topology
US20050275373A1 (en) * 2004-06-09 2005-12-15 Guang Huang T Multiple cell battery charger configured with a parallel topology
US20050275374A1 (en) * 2004-06-09 2005-12-15 Guang Huang T Pseudo constant current multiple cell battery charger configured with a parallel topology
US8436583B2 (en) 2004-06-09 2013-05-07 Icc-Nexergy, Inc. Multiple cell battery charger configured with a parallel topology
US8860372B2 (en) 2004-06-09 2014-10-14 Icc-Nexergy, Inc. Multiple cell battery charger configured with a parallel topology
US7394225B2 (en) 2004-06-09 2008-07-01 International Components Corporation Pseudo constant current multiple cell battery charger configured with a parallel topology
US8568921B1 (en) 2004-08-18 2013-10-29 Excellatron Solid State Llc Regenerative ion exchange fuel cell
US20060082345A1 (en) * 2004-08-26 2006-04-20 Josef Daniel-Ivad Rechargeable alkaline battery with overcharging protection
US20080309295A1 (en) * 2004-09-24 2008-12-18 Conceptin Et Developpement Michelin S.A. Detachable Charge Control Circuit for Balancing the Voltage of Supercapacitors Connected in Series
EP1641099A1 (en) * 2004-09-24 2006-03-29 Conception et Développement Michelin S.A. Detachable charge control circuit for balancing the voltage of supercapacitors connected in series
WO2006032621A1 (en) * 2004-09-24 2006-03-30 Conception Et Developpement Michelin S.A. Detachable charge control circuit for balsncing the voltage of supercapacitors connected in series
US8228044B2 (en) 2004-09-24 2012-07-24 Conception Et Developpement Michelin S.A. Detachable charge control circuit for balancing the voltage of supercapacitors connected in series
US7199488B1 (en) * 2004-10-14 2007-04-03 Baker David A Telemetry power system
US7928691B2 (en) 2004-11-10 2011-04-19 EaglePicher Technologies Method and system for cell equalization with isolated charging sources
US20090309544A1 (en) * 2004-11-10 2009-12-17 Eaglepicher Technologies, Llc Method and system for cell equalization with switched charging sources
US20060097700A1 (en) * 2004-11-10 2006-05-11 Eaglepicher Technologies, Llc Method and system for cell equalization with charging sources and shunt regulators
US20090267565A1 (en) * 2004-11-10 2009-10-29 Eaglepicher Technologies, Llc Method and system for cell equalization with charging sources and shunt regulators
US7825629B2 (en) 2004-11-10 2010-11-02 EaglePicher Technologies Method and system for cell equalization with charging sources and shunt regulators
US20060097697A1 (en) * 2004-11-10 2006-05-11 Eaglepicher Technologies, Llc Method and system for cell equalization with switched charging sources
US7821230B2 (en) 2004-11-10 2010-10-26 EaglePicher Technologies Method and system for cell equalization with switched charging sources
US20060097696A1 (en) * 2004-11-10 2006-05-11 Eaglepicher Technologies, Llc Method and system for cell equalization with isolated charging sources
US7540886B2 (en) 2005-10-11 2009-06-02 Excellatron Solid State, Llc Method of manufacturing lithium battery
US20090098281A1 (en) * 2005-10-11 2009-04-16 Ji-Guang Zhang Method of manufacturing lithium battery
US8222864B2 (en) 2007-04-20 2012-07-17 Sony Corporation Battery system including two or more unit cells electrically connected in series
US8035344B2 (en) * 2007-04-20 2011-10-11 Sony Corporation Battery system including two or more unit cells electrically connected in series
US20080258684A1 (en) * 2007-04-20 2008-10-23 Sony Corporation Battery system
US9356317B2 (en) 2007-06-29 2016-05-31 Johnson Ip Holding, Llc Amorphous ionically conductive metal oxides and sol gel method of preparation
US8211496B2 (en) 2007-06-29 2012-07-03 Johnson Ip Holding, Llc Amorphous lithium lanthanum titanate thin films manufacturing method
US20090004371A1 (en) * 2007-06-29 2009-01-01 Johnson Lonnie G Amorphous lithium lanthanum titanate thin films manufacturing method
US20090092903A1 (en) * 2007-08-29 2009-04-09 Johnson Lonnie G Low Cost Solid State Rechargeable Battery and Method of Manufacturing Same
US20090239132A1 (en) * 2008-03-20 2009-09-24 Excellatron Solid State, Llc Oxygen battery system
US9034525B2 (en) 2008-06-27 2015-05-19 Johnson Ip Holding, Llc Ionically-conductive amorphous lithium lanthanum zirconium oxide
US20110053001A1 (en) * 2008-06-27 2011-03-03 Excellatron Solid State Llc Ionically-conductive amorphous lithium lanthanum zirconium oxide
US20110175573A1 (en) * 2008-08-28 2011-07-21 Tomoyoshi Ueki Assembled battery and assembled battery control system
US9196932B2 (en) * 2008-08-28 2015-11-24 Toyota Jidosha Kabushiki Kaisha Assembled battery and assembled battery control system
US20110003182A1 (en) * 2009-07-06 2011-01-06 Amperex Technology Limited Connection scheme for multiple battery cells
US9005788B2 (en) 2009-07-06 2015-04-14 Amperex Technology Limited Management scheme for multiple battery cells
US9853462B2 (en) 2009-07-06 2017-12-26 Amperex Technology Limited Connection scheme for multiple battery cells
US20110089902A1 (en) * 2009-10-21 2011-04-21 K2 Energy Solutions, Inc. Circuitry for balancing charging of series connected battery cells
US20100141210A1 (en) * 2009-12-07 2010-06-10 Remy Technologies, L.L.C. Alternator for charging multiple electric storage devices
US9240696B2 (en) 2010-07-15 2016-01-19 Zpower, Llc Method and apparatus for recharging a battery
US8866412B2 (en) 2011-01-11 2014-10-21 Braxton Engineering, Inc. Source and multiple loads regulator
US9793525B2 (en) 2012-10-09 2017-10-17 Johnson Battery Technologies, Inc. Solid-state battery electrodes
US9466991B2 (en) 2013-04-25 2016-10-11 Industrial Technology Research Institute Matrix charger apparatus and charging method

Also Published As

Publication number Publication date Type
US5747964A (en) 1998-05-05 grant

Similar Documents

Publication Publication Date Title
US3543043A (en) Battery protection system
US3160805A (en) Battery charger
US6051955A (en) Protection circuit and battery unit
US5204608A (en) Battery pack including electronic power saver
US6222346B1 (en) Battery protection device
US4727306A (en) Portable battery charger
US5998966A (en) Microcontrolled battery charger
US6172482B1 (en) Battery protection circuit and electronic device
US6492792B1 (en) Battery trickle charging circuit
US6326771B1 (en) Buffer battery power supply system
US4009429A (en) Charger with multiple attachable cellholder modules
US4910103A (en) Battery pack for a portable radiotelegraphic unit
US20050017676A1 (en) Portable device and semiconductor device
US4628243A (en) Battery charging system having means for distinguishing between primary and secondary batteries
US5179337A (en) Over-discharge protection for rechargeable batteries
US4949028A (en) Multiple voltage battery charge balancing and load protecting device
US20030076642A1 (en) Over-voltage protection circuit
US5569550A (en) Battery pack having under-voltage and over-voltage protection
US5583384A (en) Method and apparatus for connecting and disconnecting a power field effect transistor
US6534953B2 (en) Battery charging apparatus, battery pack and method for charging secondary battery
US6417646B1 (en) Circuit for monitoring cells of a multi-cell battery during charge
US5568038A (en) Portable electric equipment and rechargeable built-in batteries
US4680527A (en) Electrical battery including apparatus for current sensing
US20060091854A1 (en) Power monitoring and balancing device
US5963019A (en) Battery pack with battery protection circuit

Legal Events

Date Code Title Description
AS Assignment

Owner name: PACKARD BELL NEC, CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ZENITH DATA SYSTEMS CORPORATION;REEL/FRAME:009075/0073

Effective date: 19970320

CC Certificate of correction
AS Assignment

Owner name: NEC CORPORATION, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PACKARD BELL NEC, INC.;REEL/FRAME:011007/0153

Effective date: 20000223

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
FPAY Fee payment

Year of fee payment: 8

FPAY Fee payment

Year of fee payment: 12

AS Assignment

Owner name: WARREN & LEWIS INVESTMENT CORPORATION, VIRGINIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NEC CORPORATION;REEL/FRAME:029216/0855

Effective date: 20120903

AS Assignment

Owner name: NEC CORPORATION, JAPAN

Free format text: NUNC PRO TUNC ASSIGNMENT;ASSIGNORS:WARREN & LEWIS INVESTMENT CORPORATION;COMMIX SYSTEMS, LCC;REEL/FRAME:037209/0592

Effective date: 20151019

AS Assignment

Owner name: NEC CORPORATION, JAPAN

Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE SECOND CONVEYING PARTY NAME PREVIOUSLY RECORDED AT REEL: 037209 FRAME: 0592. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT;ASSIGNORS:WARREN & LEWIS INVESTMENT CORPORATION;COMMIX SYSTEMS, LLC;REEL/FRAME:037279/0685

Effective date: 20151019